* Set proper AVR part for USBasp avrdude flashing
* Remove `PROGRAM_CMD` stuff from rules.mk as they should not be needed anymore
* Missed the Plaid readme
* Remove PROGRAM_CMD from Mysterium
* Add compatibility for LAYOUTS = planck_mit planck_grid
* Add compatibility for LAYOUTS = ortho_4x12
* Remove planck_grid community support from Plaid